Subterranean formations can be stimulated using hydraulic fracturing treatments. In some hydraulic fracturing treatments, a fracturing fluid is pumped into a portion of a subterranean formation at a rate and pressure sufficient to create fractures in the formation.
Sometimes, particulate solids are suspended in a fracturing fluid and deposited into these fractures under pressure. Particulate solids, also called “proppant particulates” or “proppants” prevent the fractures from fully closing once the hydraulic pressure of the fracturing fluid is removed or reduced. By keeping the fractures from fully closing, the proppant particulates help form conductive paths through which fluids produced from the formation can flow.
The success of a fracturing operation can depend in part on the conductivity and porosity of the formation after stimulation is complete and production begins. Traditional fracturing operations place proppant particulates into a fracture to form a “proppant pack” to prevent the fractures from closing completely after the hydraulic pressure applied to the formation has been reduced or removed. The ability of proppant particulates to maintain a fracture open depends in part on the ability of the proppant particulates to withstand fracture closure without being crushed and therefore can be proportional to the strength and volume of proppant particulates placed in the fracture.
The porosity of a proppant pack within a fracture is created by the interconnected interstitial spaces between proppant particulates. Produced fluids can flow through these interstitial spaces. Thus, proppant particulates should remain in place within the fracture and the interstitial spaces between them must be open such that fluids may freely flow through the fractures and in the spaces between the proppant particulates.
Sometimes, the near-wellbore region of a fracture can become obstructed. Proppant particulates and other formation solids can flow back during stimulation, production or both and cause buildup in the near-wellbore region of the fracture. The result is reduced interstitial spaces in the near-wellbore region of the proppant pack, which can cause a plugging effect that can reduce the conductivity of a fracture in a subterranean formation.